Large file issue


I've recently run across a problem reading large NetCDF files, and I'm
hoping someone can tell me what I'm doing wrong.

I'm using the MEXNC utility within Matlab to create several NetCDF files
on my Windows machine.  These are large files ranging from 1 to 30 GB.
I can create these files without any problem.  However, when I try to
read from them, I get an error on files greater than 2 and less than
4GB, greater than 6 and less than 8GB, greater than 10 and less than
12GB, etc.  The error string I get back is: "Arg list too long".  I get
the same error whether I try to open the files using MEXNC in Matlab, or
whether I use the ncdump.exe utility.  The same problem persists when I
try and open these files on other Windows machines, but I was able to
successfully open and read all the files on a co-workers Linux machine.

Up to this point, all the systems were running NetCDF version 3.6.0.

I then up graded to version 3.6.1, but the same problem remained,
whether I used the pre-built DLL or whether I built it myself in Visual
Studio .NET 2003.  On a whim, I decided to try the pre-built 3.6.1-beta
version of NetCDF, and suddenly I was able to open and read all the
files without error.

I'd really like to get this working with either 3.6.0 or 3.6.1.  I spent
some time going through the 3.6.1 source code, and it looks like the
ncio_filesize function (in posixio.c) is making a call to fstat, when it
should be making a call fstat64, and so it's not getting the correct
file size for files larger than 2GB.  I been reading through the Large
File Support help page, but I can't find anything that matches this
problem.  It seems like I must be setting a compiler flag incorrectly or

Any help would be appreciated.  Thanks.

Simon Hathaway

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